The present invention relates to methods and systems of processing organic waste material.
Organic waste material, such as municipal wastewater or livestock manure, can present problems when generated on a large scale. Organic waste material can be a health risk and a nuisance. Decomposing organic waste can also release greenhouse gases, such as methane and carbon dioxide, and can be a source of air and water pollution. Strategies for dealing with organic waste in large qualities are therefore needed.
Organic waste material can be converted into useful products or can have useful products extracted from it. This conversion can be done within waste conversion facilities, such as, for example, an anaerobic bio-digester. Anaerobic bio-digesters generally process the organic material by treatment with organisms, which can be obligate or facultative bacteria and/or archaea. These organisms can, using biochemical reactions, convert organic material into a variety of products. Among these products are a mixture of gases, generally referred to as biogas, and a mixture of liquids and solids, generally referred to as biodigestate.
Biogas can include methane, carbon dioxide, and amounts of other gases. Biogas can be burned to provide electricity locally, and can also be transferred to utility companies or transmission networks as natural gas. However, biogas from an anaerobic bio-digester can contain impurities that must be removed before transmission to utility companies. These impurities, which can include carbon dioxide and nitrogen, can be harmful to the environment and are generally disposed of as waste products.
Concerns about overuse of fossil fuels, based in part on environmental concerns and their substantially non-renewable nature, have generated interest in biological sources of energy. Biological energy sources can be desirable because the processes used to produce or extract them are generally less damaging to the environment. Biological energy sources can also be renewable because they are generally derived from plant and/or animal material.
Bio-production facilities can use biological organisms and processes to generate useful products, including biological energy sources, from raw materials. Examples of bio-production facilities include ethanol plants and bio-diesel plants. In bio-production facilities, feedstock is provided to organisms, such as yeasts or algae, which use biochemical processes to generate products that can be useful, such as ethanol or triglycerides, respectively.
One problem common to stand-alone waste conversion facilities and bio-production facilities is that both use products that must be acquired from external sources. These products include feedstock for the bio-production facilities, and organic material for waste conversion facilities. Importing products from external sources can cause loss of efficiency (caused by down-time and need to transport, for example) and can incur significant expenses on the operation of these facilities.
In view of the foregoing, it would be desirable to provide a system that can improve efficiency and performance of waste conversion facilities, bio-production facilities, and other facilities by reducing reliance upon external sources of materials. It would also be desirable to provide a system that reduces the need to dispose of by-products and waste products generated in waste conversion facilities, bio-production facilities, and other facilities.